664394424 has 64 divisors (see below), whose sum is σ = 1694784000. Its totient is φ = 217002240.

The previous prime is 664394417. The next prime is 664394429. The reversal of 664394424 is 424493466.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664394429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 262284 + ... + 264804.

It is an arithmetic number, because the mean of its divisors is an integer number (26481000).

Almost surely, 2^664394424 is an apocalyptic number.

It is an amenable number.

664394424 is an abundant number, since it is smaller than the sum of its proper divisors (1030389576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664394424 is a wasteful number, since it uses less digits than its factorization.

664394424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2748 (or 2744 counting only the distinct ones).

The product of its digits is 497664, while the sum is 42.

The square root of 664394424 is about 25775.8496271219. The cubic root of 664394424 is about 872.5868416010.

The spelling of 664394424 in words is "six hundred sixty-four million, three hundred ninety-four thousand, four hundred twenty-four".